the suspicious letter a dressed to president obama was found at the same facility where a letter to senator roger wicker was found yesterday, a processing facility in suburban maryland where congressional mail is tested before going to the capital. an employee noticed a white substance on the letter and hazmat team was seen pulling up to the building. initial field tests for ricin showed mixed results. no one at the facility became ill. >> when preliminary tests are done, secondary -- and i suppose tertiary tests are made because of the need for accuracy and to be sure about what the substances might be. >> reporter: in a bulletin obtained by the "associated press" the fbi says the letters to obama and senator wicker were postmarked memphis, tennessee, both letters say, quote, to see a wrong and not expose it is to become a silent partner to its continuance. both are signed, i am kc and i approve this message. >> reporter: investigators are giving few details about the case but wicker's colleague, senator claire mccaskill, says police have a suspect. she told reporters, quote, the person th